"When the Minister of Housing comes out and says things like if property investors don't like the changes, they should invest their money elsewhere. I personally think he should be careful what he wishes for."

Phil Twyford has previously said he expects some landlords will sell-up rather than abide by the new rules, but reckons that's a good thing because they'll either sell to first-home buyers or more responsible landlords.

Phil Twyford.
Photo credit: The AM Show

Ms Roberts says the former is not necessarily a good thing, because it reduces the number of homes available to rent.

"Sixty percent of the renters in this country are renting because they can't afford to buy," she told The AM Show.

"If there are rental properties that are going to get sold to home buyers, that's good for the home buyers, sure - but on average there are 2.1 people that live in a home-owned dwelling, but rental properties on average [have] 3.9 tenants. So if a rental property with four tenants gets sold to a home buyer, that's potentially four more people who need to find a new rental."

She didn't comment on whether an increased number of homes going on the market would drive prices down and making it possible for renters to get on the property ladder. Prices in Auckland have stalled this year, after a long period of double-digit growth. Rent increases have also outpaced wages over the past decade, but not quite as much as purchase prices.

Mr Twyford says evidence from overseas suggests the new tenant-friendly rules won't result in rent increases, as Andrew King of the Property Investors Federation claimed on The AM Show earlier this week - his estimate was about $20 a week on average.

"The Government has already done a bunch of well-meaning things in terms of healthy things, taxes and the like on landlords. What do the landlords do? I'll tell you what they do - they pass the cost on to the poor old renter. So by being kind, they're being cruel."

Ms Roberts has similar thoughts.

"The Government's got the right idea and their intentions are good, but they're trying to fix a problem by punishing the good people… If they want to keep market rents down, they need more private landlords. They don't need to be making things more difficult."

Public consultation ends at 5pm on Sunday, October 21. Any changes that result are likely to come in force in 2020.